IL4 and cutaneous leishmaniasis: An association of functional polymorphisms in four cytokine genes with susceptibility to, and clinical outcome of cutaneous leishmaniasis has been shown, suggesting that functional genetic variants in the interleukin 4 (IL4) promoter could influence the risk of developing cutaneous leishmaniasis while the polymorphism in the first intron of the interferon (IFN)-gamma gene might influence the progression of disease towards chronic cutaneous leishmaniasis [24].